The overall objective of this investigation is to determine whether a relationship exists between alterations in steroid hormone-tissue interactions and certain diseases of the oral tissues. This will involve further study of hormone-receptor function and receptor related events, steroid hormone (androgens, estrogens, progestins and corticoids) metabolism and investigations into the mechanism by which these hormones and certain drugs such as dilantin, which influence steroid metabolism, cause clinical and histological changes of the oral tissues. The endocrine status of the patients involved in the study, including detailed blood hormone levels, will be correlated with the clinical, histopathological and biochemical changes in the periodontal tissues. This research will be carried out in both animals and in normal and diseased human tissues. It is hypothesized that defects of steroid metabolism found in diseases of the oral tissues may be of pathogenetic significance in these disorders.